The present invention relates to a method for self-testing and mutual testing of multifunctional remote control transmitters used to control household appliances such as stereos and televisions; and particularly to a method for improving reliability of the transmitting and receiving conditions of the multifunctional remote control transmitter having an infrared receiver therein by self-testing and mutual testing.
An ordinary multifunctional remote control transmitter disclosed in U.S. Pat. No. 4,623,887 is illustrated in FIG. 1. Referring to FIG. 1, to learn, store and retransmit a remote control code transmitted from any other similar remote control transmitter, the multifunctional remote control transmitter comprises microprocessor 1, infrared receiver 2, signal converter 3, infrared transmitter 4, expanded memory 5, key selector 6, display 7 and battery check unit 8. The microprocessor 1 controls the entire system of the multifunctional remote control transmitter. The infrared receiver 2 detects and amplifies a signal transmitted from any other remote control transmitter. The signal converter 3 converts a signal received by the infrared ray receiver 2 into a signal that the microprocessor 1 can analyze. The infrared transmitter 4 converts an electric signal transmitted from the microprocessor 1 to a light signal and then transmits it. The expanded memory 5 stores code information entered from the infrared receiver 2 and the key selector 6 inputs a key selection signal to the microprocessor 1. The display 7 is a liquid crystal device (LCD) to display received data from the microprocessor 1. The battery check unit 8 transmits a battery detecting signal to the microprocessor 1. The reference number 9 in FIG. 1 represents a light emitting diode (LED) and number 10 represents a memory back-up circuit for maintaining the memory state of the expanded memory 5 during absence of power.
The ordinary multifunctional remote control transmitter, however, has drawbacks that make it difficult to detect circuit malfunction caused by poor soldering and misalignment; and to test the remote control transmitter itself or any other remote control transmitter.